/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2001 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" and
 *    "Apache Lucene" must not be used to endorse or promote products
 *    derived from this software without prior written permission. For
 *    written permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
 *    "Apache Lucene", nor may "Apache" appear in their name, without
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 *
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 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

using System;
using System.Collections.Generic;

using DotnetPark.NLucene.Store;

namespace DotnetPark.NLucene.Index
{
	internal class SegmentInfos 
	{
		public int counter = 0;			  // used to name new segments
		public List<SegmentInfo> segs = new List<SegmentInfo>();
  
		public SegmentInfo Info(int i) 
		{
			return this.segs[i];
		}

		public void Add(SegmentInfo si)
		{
			this.segs.Add(si);
		}

		public int Count
		{
			get
			{
				return this.segs.Count;
			}
		}

		public void RemoveRange(int start, int end)
		{
			this.segs.RemoveRange(start, end);
		}

		public void Read(Directory directory) 
		{
			InputStream input = directory.OpenFile("segments");
			try 
			{
				counter = input.ReadInt();		  // read counter
				for (int i = input.ReadInt(); i > 0; i--) 
				{ // read segmentInfos
					SegmentInfo si = new SegmentInfo(input.ReadString(), input.ReadInt(),
						directory);
					this.segs.Add(si);
				}
			} 
			finally 
			{
				input.Close();
			}
		}

		public void Write(Directory directory) 
		{
			OutputStream output = directory.CreateFile("segments.new");
			try 
			{
				output.WriteInt(counter);			  // write counter
				output.WriteInt(this.segs.Count);			  // write infos
				for (int i = 0; i < this.segs.Count; i++) 
				{
					SegmentInfo si = Info(i);
					output.WriteString(si.Name);
					output.WriteInt(si.DocCount);
				}
			} 
			finally 
			{
				output.Close();
			}

			// install new segment info
			directory.RenameFile("segments.new", "segments");
		}
	}
}
